Bearing for angle attachments for dental handpieces



July 24, 192s. 1,678,097

L, B. ANDRESEN BEARING FOR ANGLE ATTACHMENTS lFOR DENTAL HANDICES k Fil'ed March 26, 1925 r TOR/vf Ys Patented July Z4, 1928A.

UNITED STA'IISI 'PATENT OFFICE.

i LAILITZ B. .ANDRESEL OF MINNEAPOLIS, MINNESOTA,"'ASSIGNR TO M. FPPATTERSON .DENTAL SUPPLY CO., OF ST. PAUL, MINNESOTA, A CORPORATION OF ILLINOIS.

BEARING `non ANGLE ATUAGHMENTS FOR nEN'rAL HANPIEoEs.

Appiieauon ined March 2e, 1925. serial No. 18,493.

provide* such an angle head having means mounted upon the burr tube thereof for the purpose of outwardly directingl away from thel bearings thereof, such foreign material as grit and saliva, thereby preventing such materialvfrom entering thel bearings and thereby causing damage thereto.

A further object is to provide such a de-"l'y vice of simple and inexpensive construction which 'may readily and conveniently be taken apart for cleaning and repairs' and" may asfreadily be re-assembled.

` Other objects of the invention will appear from the following description and the accoinpauyiiig drawings vand will be pointed' out in the annexed claims.

` In the drawings, there has been disclosed astructure designed to carry out the various 1 objects of the invention but it is to be under stood that the invention is not confined to the exact features shown as various changes may be made within the scope of the claims which follow.

In the drawings: Figure 1 is a. partial sectional View of an angle head showing the novel dust and gritproof bearing mounted therein;

` rFigure 2 is a view of the head removed from its supporting means and also showing the lower bearings and burr tube removed i from the head Figure 3 is a view kshowing the burr tube tion here' shown "there :is illustrated an angle head similar to the dnefeatured in my prior pending application' Serial No. 18,4921iled March 16, 1925.` This angle head comprises the usual head@ having a cylindricalendportion -7 formed thereon" `which iszreceived in threaded engagement in a couplingsleeve v8 having its other end received in threaded engagement upon one end of a supporting member 9 of ordinary construction." The I'coupling sleeve Sis provided with riglitand left handed threads so that when it is roftated in one direction'theheadi will be released or unlocked and wlienfrotated inthe -opposite direction, it vwillbe securely locked to the supporting member l9 in iftsadjuls'ted position. Thefusual latch 11 isalso shown pivotally mounted upoi'i af'stud 1 2 secured to the ,head 6." .This latch functions toy retain the tool ,orA burr in the head 'when the lnstrumenty is being used.

AAn important feature of kthis invention residesin the novel. constructionfo'f the lower bearing `for theiburr" tube 13 rotatably mounted in th'ehead 6. `Theburr -tube 13 is provided 'with th'eusual beveled pinion 14 `adapted to mesh with a pinion 15 mounted `upon a shaft 16Vwhic`h is mounted in suit-V able bearings, notfshown. As shown in-Figure 3, the lower bearing 17 is preferably mounted upon the lower end-portion" 18 of the bui'rtube 12vj and is retained thereon by means ofa dustfcap 19' whichispreferably fixe'dly mounted upon the'" lower end-portion `18 of thetube byfsuch 'means as being pressed thereon *The bearing'17 is provided with an annular groove 21 adapted to receive a correspondinglyshaped tongue 22 provided on the `dust cap 19. This tongue and groove arrangement functions to preveiitdust and grit from creeping into the bearing when the tool lis in use. The upper end-portion 23 ofthe bearing 17 is preferably provided witlilthreads 241 adapted to be received in similar threads Qfprovided in the bore of the head 6 as shown in Figure 2.

The bearing 17 is also preferably knurled as shown at 26 in Figure 4, so that it may readily be secured to the threads 25 in the head.

A bearing 27 is mounted iii the upper portion of the head 6 to support the upper end of the burr tube 13, By reference to Figures 1 and 3, it will be noted that the upper end of the burr tube is preferably turned down so as to be received in the upper bearing 27 as shown in Figure 1. A flange 28 is also provided on the burr tube to take up the end thrust of the tube when inL use.

1n assembling the angle head, the bearing 17 will first beinounted upon the lower endportion of the burr tube with its upper `end" or face abutting the 'shoulders 29 lprovided b y the lower portion of the pinion or gear 14. The dust cap 19 will then bel pressed onto theend-portion 18 of the tube until it. substantially contacts with the lowei face of,

the bearing 17, siiilicient clearance between the two, however, being allowed so as to providey a free running fit for tie shoulder 29 and the upper face of the dust cap 19. Theburr tube with the bearing 17-and dust cap 19 assembled thereon, will then be inserted into the head 6 and the bearing 17 secured thereto by means .of the threads 2st and 25, it being understood of course that theupper reduced end-portion of the tube 13 will enter the upper bearing 27 as shown in Figure 1. lVhen the headhas thus been assembled, it will be impossible for any dust or grit to enter oi' work into the lower bearing when the burr tube is being rotatedrfhis By the employment of this novel bearing construction or method oi' supporting the burr tube within the angle head, it will be impossible for any dust or grit to work into the bearing and' cause damage thereto.`

This is accomplished by means of the tongue 22 of the cap 19 fitting into and rotating in the annular groove 21 in the lower bearing 17, and also as a result ot the centrifugal action of the cap 19 which action tends to outwardly direct away from thel bearing all saliva and grit coming ineontact therewith. By tliiis preventing dust and grit it'rom enteringthe lower bearing' the lite ot the instrument will be O'reatl arolone'ed e .Y e

as compared with similar instruments, 'ot

Lemos?" with other types of bearings and must therefore have frequent` bearing replacement Lor repairs as a result of saliva and grit working into thebearings and causing damage thereto.

Having thus described my invention whatv ordinary construction, which are provided I claim as new and desire tok secure by Letf ters-Patent, is:

1. A dental tool head, `a burr tube having bearings in said head, one of said bearings having an annular groove, and means mountedy on said tube and rotatable in said groove, andy cooperating therewith to exclude foreign'material from said bearing.

2. A dental rtool head in combination with a burr tube having bearings therein, a meinber mounted on said tube and having means interlocking with one of said bearings to `form a tortuous passage between them to prevent the entrance of dust andgrit into said bearing.

3. The' combination with a dental tool head, ot burr tube mounted for rotation therein, and having a bearing adjacent its tool-receiving end, said ybearing having an annular groove therein, and said tube having a ineinber provided with an annular rib to enter said groove and rotate therein, the` revolution ,of said tube and member operatingto directioreign material outwardly from the passage between said member and bearing.

et, A dental tool head having a cylindrical recess therein, a burr-holder adaptedrotatably to be received within the recess, a bearing tor the burr-holder demountably secured and adapted demountably to retain the burr-holder in vits operable position, andy a tongue-and-groove device encircling the tool-end ot the burr-holder to prevent entrance of foreign material to the bearing -5. A dent-al tool head having a bearing therein, a burr' tube rotatably mounted in the bearing, a circular memberk terminally secured to tlietube exteriorly of the head and in close proximity with the bearing, an annular groove in the face of said bearing, and an annulartongue on said circular inember engaging said groove to prevent ioreign material from entering the bearing.

ln witness whereof, I have hereunto set my handthis 21st day of March, 1925.

, n LAURITZ B. ANDRESEN.

. to the head and extending within the recess 

